I know that the universe is 13 billion years old and the fastest anything could be is the speed of light so if the universe is expanding as fast as it could be wouldn’t the universe be 13 billion light years big? But I’ve searched and it’s 93 billion light years big, so is the universe expanding faster than the speed of light?
In: 938
We do not know how big the universe is. We can only say anything about the **observable** universe. The 93 billion light years is the current size of the observable universe and is based on a few different factors. Firstly the 13 billion light years is from us to one edge, so this is the radius of the observable universe. You have to double this to get the diameter of the observable universe. In addition the objects we can observe now might have been moving at the speed of light away from us. So they are not 13 billion light years away but rather 26 billion light years away. So the size of the observable universe is then 52 billion light years. The last factor is a bit more complex but basically since space is expanding the amount of space that light went through in a light year have now expanded. So the space which used to be 13 billion light years as the light passed through it is now closer to 23 billion light years.
Latest Answers